EP 0000495 B1 19801126 - PROCESS FOR THE PREPARATION OF 1-AMINO-8-HYDROXY NAPHTHALENE-3,6-DISULPHONIC ACIDS (H-ACIDS).
Title (en)
PROCESS FOR THE PREPARATION OF 1-AMINO-8-HYDROXY NAPHTHALENE-3,6-DISULPHONIC ACIDS (H-ACIDS).
Publication
Application
Priority
DE 2732266 A 19770716
Abstract (en)
[origin: US4166826A] A process has been invented for the preparation of a mono-alkali metal of 1-amino-8-naphthol-3,6-disulphonic acid, comprising reacting 1-naphthylamine-3,6,8-trisulphonic acid and/or a salt thereof and/or a naphthylamine trisulphonic acid isomer mixture and/or salt thereof with an alkali metal hydroxide solution in the presence of an alcohol and/or alcoholate and in the presence of a substance which contains at least one oxygen atom bonded to a nitrogen atom, at elevated pressure and elevated temperature, and separating out the mono-alkali metal salt of 1-amino-8-naphthol-3,6-disulphonic acid by acidification. The process results in the procurement of higher yields of the desired product and in the formation of less by-products.
IPC 1-7
IPC 8 full level
C07C 67/00 (2006.01); C07C 309/50 (2006.01); C07C 301/00 (2006.01); C07C 303/22 (2006.01); C07C 303/32 (2006.01)
CPC (source: EP US)
C07C 303/22 (2013.01 - EP US)
C-Set (source: EP US)
Designated contracting state (EPC)
BE CH DE FR GB
DOCDB simple family (publication)
EP 0000495 A1 19790207; EP 0000495 B1 19801126; BR 7804542 A 19790320; DE 2732266 A1 19790201; DE 2860341 D1 19810212; IT 7850308 A0 19780714; JP S5419955 A 19790215; US 4166826 A 19790904
DOCDB simple family (application)
EP 78100358 A 19780711; BR 7804542 A 19780714; DE 2732266 A 19770716; DE 2860341 T 19780711; IT 5030878 A 19780714; JP 8525678 A 19780714; US 92003278 A 19780628